#include???
#include???
#include???
#include???
#include???
#include???
#include???
#include?

int?main（int?argc?char*?argv[]）?{??
???
	int?sin_len;???
	int?socket_descriptor;??
	int?port;?
	struct?sockaddr_in?sin;?
??????
?	if?（argc?!=?2）{
		printf（“Usage:?sound_recv??PORT?\n“）;
		exit（1）;
	}
	port?=?atoi（argv[1]）;
	int?rc;
	int?dir;
	int?size;
	snd_pcm_t?*handle;
	snd_pcm_hw_params_t?*params;
	snd_pcm_uframes_t?frames;
	unsigned?int?val;
	char?*buffer;
?	printf（“Waiting?for?data?form?sender?\n“）;??
??
	bzero（&sinsizeof（sin））;??
	sin.sin_family=AF_INET;??
	sin.sin_addr.s_addr=htonl（INADDR_ANY）;??
	sin.sin_port=htons（port）;??
	sin_len=sizeof（sin）;??
	socket_descriptor=socket（AF_INETSOCK_DGRAM0）;??
	bind（socket_descriptor（struct?sockaddr?*）&sinsizeof（sin））;??



	/*?Open?PCM?device?for?playback.?*/
	rc?=?snd_pcm_open（&handle?“default“
				SND_PCM_STREAM_PLAYBACK?0）;
	if?（rc?	fprintf（stderr
			“unable?to?open?pcm?device:?%s/n“
		snd_strerror（rc））;
		exit（1）;
	}

	/*?Allocate?a?hardware?parameters?object.?*/
	snd_pcm_hw_params_alloca（¶ms）;

	/*?Fill?it?in?with?default?values.?*/
	snd_pcm_hw_params_any（handle?params）;

	/*?Set?the?desired?hardware?parameters.?*/

	/*?Interleaved?mode?*/
	snd_pcm_hw_params_set_access（handle?params
??????????????????????	SND_PCM_ACCESS_RW_INTERLEAVED）;

	/*?Signed?16-bit?little-endian?format?*/
	snd_pcm_hw_params_set_format（handle?params
??????????????????????????????	SND_PCM_FORMAT_S16_LE）;

	/*?Two?channels?（stereo）?*/
	snd_pcm_hw_params_set_channels（handle?params?1）;

	/*?44100?bits/second?sampling?rate?（CD?quality）?*/
	val?=?44100;
	snd_pcm_hw_params_set_rate_near（handle?params
?????????????????????????????????		?&val?&dir）;

	/*?Set?period?size?to?16?frames.?*/
	frames?=?32;
	snd_pcm_hw_params_set_period_size_near（handle
?????????????????????????????	?params?&frames?&dir）;

	/*?Write?the?parameters?to?the?driver?*/
	rc?=?snd_pcm_hw_params（handle?params）;
	if?（rc?		fprintf（stderr
			“unable?to?set?hw?parameters:?%s/n“
		snd_strerror（rc））;
	exit（1）;
	}

	/*?Use?a?buffer?large?enough?to?hold?one?period?*/
	snd_pcm_hw_params_get_period_size（params?&frames
???????????????????????????????????			?&dir）;
	size?=?frames?*?2;?/*?2?bytes/sample?1?channels?*/
	buffer?=?（char?*）?malloc（size）;

	/*?We?want?to?loop?for?5?seconds?*/
	snd_pcm_hw_params_get_period_time（params
???????????????????????????????????		?&val?&dir）;
?
	while（1）??
	{???????
		rc?=?recvfrom（socket_descriptorbuffersize0（struct?sockaddr?*）&sin&sin_len）;?
		fprintf（stderr
			“?%s/n“
		snd_strerror（rc））;??
		rc?=?snd_pcm_writei（handle?buffer?sizeof（buffer））;??????????
????????}??

??
????
???
??
??
	close（socket_descriptor）;??
	snd_pcm_drain（handle）;
	snd_pcm_close（handle）;
	free（buffer）;
	return?0;
}